Smoke from exhaust, intake gasket, rings, or valve guides
 

Hello,

I have 1979 L82, stock with 44k miles on it.

We put new exhaust on it and I was taking a video and I noticed some smoke coming out of the pipes after revving, not every rev, only at the end. Now this motor always puffs when we first start it (I think valve guides issue) but this was the first time seeing this.

If it was rings i would think every time the car is revved it would smoke, not just some times. Also I checked and there is no smoke coming from dipstick tube when I pull the stick. I also didnt see any smoke when I revved the car to 4k rpm in first gear and let off (but I was in driver's seat)

Additionally we the motor doesn't like to idle very well when cold and it used to smoke near the valve covers, the mechanic sprayed around the intake gaskets and it picked the revs up, so we had a bit of a gasket leak there (he retorqued the intake and it no longer smokes at the valve covers but maybe the oil is now finding it's way into the cylinder rather than onto the valve covers?

Video:
https://youtu.be/iu7iJxtauDk

What are your thoughts?

Thanks,
Miller

Might be the valve seals need to be replaced. I did mine on my 77 L48 and used the umbrella style and no more smoke. My car had symptoms very much the same as yours.

The Bore Scope Cameras are pretty cheap these days you can look in the spark plug holes at the pistons. If there is carbon on top all the way out to the edge then the rings are fine. If the Piston is clean (from oil not letting the carbon stick) out near the cylinder then the rings are leaking. It could be a bad PCV valve. Find where the PCV is plumbed into the Manifold and look down threw the Carb with the camera for Oil. Sounds like it had some sort of Intake Gasket leak in the past and they never got replaced. So they could be letting Oil get sucked in. Those Gaskets and Valve Seals are 38 years old and getting brittle.

Thanks for the info. I am using oil on my recently rebuilt 78 L82. I didn't know about using the bore-scope to look at the top of the pistons.

I have a 77' with the L-82 and it happens to me on a restart. If I go for a ride, shut her down and let it an hour or two. I would get a puff of smoke on a restart. It doesn't happen if the car sat all day at a show or over night. I don't get any smoke while I'm driving... I was told my valve seals are shot, the seals only cost like 20 bucks or so..